U0 " Outdoor Unit: Gas Shortage Alert - Daikin VRV III REYQ8PY1 Service Manual

Troubleshooting by Indication on the Remote Controller
U0
3.44 " " Outdoor Unit:
U0
Remote
Controller
Display
Applicable REYQ8P~48P
Models
Method of Detect gas shortage based on the temperature difference between low pressure or suction pipe
and heat exchanger.
Malfunction
Detection
Malfunction [In cooling mode]
Low pressure becomes 0.1MPa or below.
Decision
[In heating mode]
Conditions
The degree of superheat of suction gas becomes 20 degrees and over.
SH= Ts1 –Te
Ts1: Suction pipe temperature detected by thermistor
Te : Saturated temperature corresponding to low pressure
★
Supposed
Causes
304
Gas Shortage Alert
Malfunction is not determined. The unit continues operation.
Gas shortage or refrigerant clogging (piping error)
Defective thermistor (R4T, R7T, R12T, R15T)
Defective low pressure sensor
Defective outdoor unit PC board (A1P)
Si37-701
Troubleshooting